1. Technical Field
The inventive concept relates to a semiconductor memory system, a semiconductor memory device and a method of operating the semiconductor memory device, and more particularly, to a semiconductor memory system including a nonvolatile memory device.
2. Discussion of Related Art
A storage device stores data according to a control of a host device such as a computer, a smart phone, a smart pad, etc. A storage device includes a device storing data in a magnetic disk like a HDD (hard disk drive), a semiconductor memory like a memory card, and more particularly, a device storing data in a nonvolatile memory.
A nonvolatile memory includes a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory, a phase-change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), etc.
However, high capacity and high speed of a storage device may hamper reliability of the storage device. For example, as the number of overlapping semiconductor chips increases, a resistance component also increases. However, if the resistance component increases too greatly, a signal waveform used to communicate with the semiconductor chips may collapse.